One Third of California's Trees Are Dead (sfgate.com)

"There are about 21 million acres of trees spread across California's 18 national forests, and the latest figures show 7.7 million of them -- more than one-third -- are dead." An anonymous reader quotes the San Francisco Chronicle: California's lingering drought has pushed the number of dead trees across the state past 100 million, an ecological event experts are calling dangerous and unprecedented in underlining the heightened risk of wildfires fueled by bone-dry forests. In its latest aerial survey released Friday, the U.S. Forest Service said 62 million trees have died this year in California, bringing the six-year total to more than 102 million.

Scientists blame five-plus years of drought on the increasing tree deaths -- tree "fatalities" increased by 100 percent in 2016 -- but the rate of their demise has been much faster than expected, increasing the risk of ecologically damaging erosion and wildfires even bigger than the largest blazes the state's seen this year.
An ecologist with the U.S. Geological Survey says that on the bright side, this gives scientists a good chance to study how trees die.

Comments

Re:What is the norm?

[hey!]

Sure there are always some dead trees in a forest, as anyone who's ever hunted or rambled in a forest knows. But one out of three? And from drought? It's not normal for the historical period.

However... There have been prehistoric droughts in California lasting decades, even centuries. Since we know this from tree rings, we know some rain must have fallen, but less than we are accustomed to as "normal" in historic times. These have been correlated to "radiative forcing", natural climate change mechanisms such as variations in the Earth's orbit and volcanic activity. Warmer Earth == drier California.